I have heard mixed results to this question. Is your seat going to be exposed to the elements or under a hard top? Reason I ask is the roadster croud tend to like marine grade vinyl upholstery because it doesn't fake in the sun and holds up very well.
That being said I found this short article that may be a help to you.


Difficulty: Moderately ChallengingInstructionsThings You'll Need:
Ratchet set
Scissors
Pencil
Paper
New seat material
Upholstery stapler
Step 1Remove the seats from your car. Whether you have bucket seats or a bench seat, every car will require a different removal method. Use a flashlight to look under the seat for a series of large bolts fastening the seat to the frame. Remove these bolts and the seats should come out.

Step 2Gently take the fabric off the seat frame. You want as much of the ruined upholstery to stay intact as possible so you can create a new pattern for your seats. Most upholstery will be fastened via a series of staples around the base, so remove these. Also pay attention to how the seat fits together.

Step 3Lay your old seat material flat on large sheets of paper. Trace around each piece in order to create a pattern from which you can create new seats. If your upholstery is in such bad shape that there are gaps in the pattern, you will have to use your imagination to fill in the remainder.

Step 4Lay these patterns over the new material and cut them out accordingly. Hold each individual piece up next to the original to make sure you did not miss any important aspects of each seat.

Step 5Apply the new material in the same manner the original was attached to the seat. This will most likely mean using staples. Replace the seats in the car and ratchet them tightly to the frames.